1. Field of the Invention
The present invention relates to a fan device for an integrated circuit and, more particularly, to an improved fan device which avoids accumulation of dust and the like.
2. Description of the Related Art
Heat transfer is an important factor to performance of integrated circuits. Although a wide variety of cooling devices have heretofore been provided, the results are not satisfactory in every respect. For example, U.S. Pat. No. 5,299,632 to Lee, issued on Apr. 5, 1994 and U.S. Pat. No. 5,309,983 to Bailey, issued on May 10, 1994 disclose heat dissipating devices comprising a motorized fan assembly which occupies a relatively large volume and thus may not be used in portable computers. U.S. Pat. No. 5,288,203 to Thomas, issued on Feb. 22, 1994, discloses a fan engaged in a fan frame member for reducing the volume of the fan, yet this adversely affects the heat transfer effect. Applicant's U.S. patent application Ser. No. 08/399,041 filed on Mar. 6, 1995 discloses a compact fan device to solve the problems in the prior art patents. Nevertheless, it is found that dust tends to accumulate in coils of the fan or other elements as an axle cap thereof which interconnects blades and which encloses a rotor shaft of the fan faces upwardly, resulting in malfunction of the fan and/or the integrated circuits as well as generation of noise during rotation of the fan. Furthermore, the amount of cool air induced by the fan is not maximized. The present invention is intended to provide an improved design to mitigate and/or obviate the above problems.